Mechanical pencil



y 7, 1936- E. J. NEARY MECHANICAL PENCIL Filed June 20,

1934 2 Sheets-Sheet 1 Ill llllll ll llllll il h r l ATTORNEY July 7,19360 NEARY MECHANICAL PENCIL Filed June 20, 1934 2 Sheets-Sheet 2ATTORN EY Patented July 7, 1936 I UNITED STATES MECHANICAL PENCIL EdwardJ. Neary, St.

J ohns, Newfoundland Application June 20, 1934, Serial No. 731,449

3 Claims.

The object of the present invention is to provide a mechanical pencil ofa type in which the lead may be propelled by reciprocating a sleevemounted on the exterior of the pencil barrel, and the specific objectofthe invention is to provide a pencil of such type which will be surein its action and inexpensively manufactured and which will holdrelatively long leads in reserve supply within the barrel of the pencil.

Further objects will hereinafter appear.

The invention will be described with reference to the accompanyingdrawings, in which Fig. 1 is a plan view of an embodiment of theinvention.

Fig. 2 is a front end elevation of the same.

Fig. 3 is an enlarged longitudinal section on the line 33, Fig. 1, withthe propelling sleeve in retracted position.

Fig. 4 is a fragmentary longitudinal section 20 showing the propellingsleeve and associated means in forward but not extreme position.

Fig. 5 is a. view similar to Fig. 4, showing the propelling sleeve inextreme forward position.

Fig. 6 is a fragmentary plan view of the front 25 portion of the pencilbarrel.

Fig. '7 is a plan view of the propelling wedges. Fig. 8 is a plan viewof the propelling sleeve. Figs. 9, 10, 11, and 12 are, respectively,transverse sections on the lines 99, I vll---I 0, I l--l I and 30 l2l2,Fig. 3.

Fig. 13 is a plan view of amodified form of the invention.

Fig. 14 is a front end view of the device of Fig. 13.

Fig. 15 is an enlarged longitudinal section of the device shown in Fig.13, partly broken away. Fig. 16 is a transverse section on the line IG-l6, Fi 15.

Fig. 17 is a plan view, partly broken away, of 40 the pencil barrel ofFig. 15.

Fig. 18 is a plan view of the propelling sleeve of the device shown inFig. 15.

Referring to Figs. 1 to 12 inclusive, I have shown a pencil formed ofmetal, or the like, and 45 comprising a barrel I longitudinallysupporting a lead tube 2 for a length of lead indicated at 3. Toward therear end of the barrel, sleeve 2 is supported by four studs 4 which maybe secured to the tube in any suitable way. and pass through 50apertures in barrel l and then headed over. The tube may be secured inany other suitable way so as to permit passage of spare leads intobarrel space surrounding lead tube 2. In the present instance, the rearend of barrel I is formed with an annular shoulder Ia: against which mayabut an eraser sleeve 5 having rolled threads 5:: for securing andholding of an eraser 6.

Toward its forward end, barrel l is reduced in diameter and the reducedforward end receives the plug-like rear end 'I of a tip member havingtwo heads 8 and spaced guide. bars 83:. Plug 1 is apertured to receivethe lead 3 which thence passes between" the guide bars 8x and through a.suitable aperture between the heads 8, the latter preferably being splitto form two opposed clamping sections.

Slidably mounted upon the barrel is a propelling sleeve 9 having in themid portion of its length inturned lips Ill adapted to bear against thereduced portion of the barrel l and to con- 15 tact with a spiral springll surrounding the barrel at such reduced portion. The tension of aspring H tends to move the propelling sleeve 9 forwardly.

Seated between the bars 81:, Fig. 6, are opposed wedges l2 preferablyheld together by any suitable arrangement such as the semi-circular'clip l3. Wedges l2 are of less length than the length of the slotprovided between the spaced bars 8:0, head 8 and plug 1, so that thewedges are free to move a certain distance longitudinally of the pencil.

In the operation of the device, the parts will normally lie in theposition of Fig. 5, in which position the frusto-conical front end ofthe propelling sleeve 9 acts as a cam device upon the split head 8 tofrictionally hold the lead in position inasmuch as the rear section ofthe split head acts in conjunction with the frusto-conical or flaringformation of the propelling sleeve front end to have wedge action andfrictional pressure upon the lead. In such position, the wedges l2 maybe idle.

When the knurled section 90: of the propelling sleeve and the sleevemove backward against the 40 tension of spring II, the propelling sleeveat its cross section of narrowest diameter will gradually engage thewedges l2 and move them backwardly to the position shown in Fig. 12, thelead remaining in position inasmuch as the action upon the wedges merelyovercomes the inertia of their Weight.

When, however, propelling sleeve 9 is moved backward a distance stillgreater, the wedges being held against longitudinal movement by abutmentwith plug I, the wedges will be given a movement toward each other untilthe lead is firmly engaged and then the lead will resist furthermovement of the wedges so that the backward thrust upon the propellingsleeve will cause the 55 latter to clampingly engage the wedges. Thuswhen the propelling sleeve is moved forward, the clamping action on thewedges will be greater than the 'slight inertia. of the lead and thelead will be moved forwardly until the wedges reach the position shownin Fig. 5 and abut split head 8. At such moment, the frusto-conicalfront end of the propelling sleeve will have reached approximately itsmaximum clamping position relatively to the tapered rear section of thesplit head 8 and the lead will be firmly gripped by the latter in thefinal forward movement of the propelling sleeve. In such final movement,the sleeve moves forward relatively to the wedges and the latter arereleased from the lead.

In Figs. 13 to 18 inclusive, I have shown a modification of my device inseveral particulars; In the first place, the propelling sleeve shown at9a is split at its front end to have a spring-like clamping action uponthe split head 8a. In such case the normal diameter of the opening atthe front end of the propelling sleeve will be less than the diameter ofthe head 8a and the latter may be of uniform diameter, bevelled towardthe lead. Also, to restrict forward movement of the propelling sleeve9a, the latter is formed with a depressed inwardly extending ring at Mso that.

the ends of the wedges |2a will act as stops by contact with ring l4when the latter is moved beyond its normal forward position. In otherrespects the pencil elements are the same as that of the precedingfigures.

In the structure of Figs. 13 to 18 inclusive, removal of the lead 3awill enable bodily inward movement of the wedges to permit assembly anddisassembly of the propelling sleeve 9a.

In the action of the modified device, movement of the propelling sleeverearwardly to the position of Fig. 15 will cause the split ends of thepropelling sleeve to meet the unbroken ring-like section 81111 of thehead 8a, thus relieving the lead of clamping pressure. Still furtherrearward movement of the propelling sleeve will cause the same to gripthe wedges In in the manner described with reference to the precedingFigures 1 to 12 inclusive, and forward movement of the propelling sleevewill cause the wedges to advance with the lead until the split end ofthe propelling sleeve passes over upon the split section of head So andagain clamps the lead. Prior to this, the wedges will have reached theend of their forward movement and will be released from the leadpreliminary to succeeding rearward movement of the propelling sleeve tofurther advance the lead.

It will be seen that the wedges carry the lead forward through themovements of the propelling sleeve, and the sleeve may extend only partof the length of the pencil, making it unnecessary to provideattachments at the rear end of the pencil, as, for example, plungers,for moving the sleeve to its various positions.

It will also be noted that the bell-shaped end of the propelling sleeveis so: formed that any line drawn longitudinally of its inner surface isstraight and in conformation with a corresponding line extendinglongitudinally of the surface of the split head 8 with which thebell-shaped end of the sleeve contacts. Thus, the propelling sleeve notonly presses the parts of the split head together, but also retains africtional grip on them, which grips the whole in clamping positionuntil the sleeve is retracted.

In the modification shown in Figs. 13 to 18 inclusive, the propellingsleeve may be of fairly heavy and springy metal, at least at the splitend section thereof, where it engages with the clamping head Ba. Theinner walls of member 8 abutting the lead may be slightly toothed,threaded or roughened so as to enable firm grip upon the lead andcorresponding formation may be given to the split head Be.

It will further be seen that the assembly of the elements is so simplethat the moving parts are held together by the insertion of the lead andreleased for disassembly by removing the lead.

In the device of Figs. 1 to 12 inclusive, insertion of the lead expandssplit head 8 to such position that it is greater in diameter than thepropelling sleeve at its minimum diameter. When the lead is removed,contraction of the split head is permitted and the sleeve may beremoved, the wedges, spring, plug and tube 2 disassembled or assembled,as the case may be.

Having described my invention, what I claim and desire to secure byLetters Patent, is as fol- 25 1. A mechanical pencil comprising a barrelhaving a lead passageway extending therethrough, a clamping head at oneend of the barrel, through which the lead passes, the head having afrusto-conical rear section, a propelling sleeve mounted upon the barrelfor endwise reciprocation the sleeve being formed with 'a flared endsection conforming with the frustoconical section of the clamping headand with a contiguous reversely tapered section merging into acylindrical portion telescoped over the main body of the barrel, and aplurality of wedges within the sleeve and between the lead passageway ofthe barrel and said head, the wedges being bodily movable toward andfrom the frustoconical section of the clamping head, and at the end oftheir movement away from said head being adapted to contact with anabutment carried by the barrel.

2. A mechanical pencil comprising a barrel formed with a longitudinalaperture for the passage of a lead, a split head projected forwardly ofthe barrel and through which the lead passes, a wedge disposedrearwardly of the split head and having endwise movement limited by awall of the head and the front wall of the barrel, and a sleeve movableupon the barrel and directly enclosing the wedge, the sleeve having anintermediate restricted section merging into reversely flared sections,one flared section being adapted to exert a compressive action upon thesplit head when the sleeve is moved forwardly, and the other taperedsection being adapted to exert a compressive force upon the wedge andthrough the wedge upon the lead when the sleeve is moved rearwardly tosuch position that an end of the wedge contacts with the said end of thebarrel.

3. A mechanical pencil constructed in accordance with claim 2, in whichthe head is formed intermediate thereof with a relatively unyieldingring section and the propelling sleeve is formed with a split springend, the sleeve when moved rearwardly bringing the spring end over uponsaid unyielding ring section of the barrel head.

EDWARD J. NEARY.

